SOLUTION: The sum of the digits of a two digit number is 15. If the digits are reversed, the result exceeds the original number by 9.Find the original number. I think the first equation is

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Question 305756: The sum of the digits of a two digit number is 15. If the digits are reversed, the result exceeds the original number by 9.Find the original number.
I think the first equation is: x + y = 15

Answer by themathtutor2009(81) About Me  (Show Source):
You can put this solution on YOUR website!
x+y=15
10y+x=10x+y+9

x+y=15
y=15-x


10y+x=10x+y+9
10(15-x)+x=10x+15-x+9
150-10x+x=10x+15-x+9
150-9x=9x+24
150-24=9x+9x
126=18x
126/18=x
7=x
x=7

y=15-x=15-7=8

Answer: number is 78